Unruly students barged into Ofsted inspectors and bombarded them with food as they inspected a struggling school, according to the watchdog's report.
The Willenhall E-ACT Academy in the West Midlands was branded "inadequate" and has been put into special measures following the chaotic visit on 7 and 8 March.
Inspectors found that a third of children in Years 7 to 11 were "disrespectful" and "regularly absent" from classes.
"Rude" children threw food at them in the canteen and in a classroom as they observed a decline in standards at the "very challenging school".
Sixth-formers were said to be too scared to leave their common room due to younger pupils' bad behaviour, while children with special educational needs tried to find safe spaces to avoid fights during break times.
The damning Ofsted report revealed 70 per cent of teachers left the E-ACT Academy, which it said was "coasting", between 2015-2016. The watchdog gave the school the lowest possible ranking – inadequate – for all inspection categories, including leadership, teaching, behaviour, outcomes for pupils and 16-19 studies.
It read: “Her Majesty’s Chief Inspector is of the opinion that this school requires special measures because it is failing to give its pupils an acceptable standard of education and the persons responsible for leading, managing or governing the school are not demonstrating the capacity to secure the necessary improvement in the school."
Litter and graffiti were found inside the school and poor behaviour "led to many pupils feeling unsafe and not learning well", according to Ofsted.
The report added: "Inspectors had food thrown at them in the canteen and in a classroom. A small number of pupils were rude to them. Inspectors were jostled in corridors and witnessed staff being ignored or defied.
"A senior leader was spoken to disrespectfully by pupils and told inspectors this was the norm.
"Pupils who have special educational needs and/or disabilities told inspectors they like to find safe places in the school because other pupils fight, push and swear at social times.
"Sixth-form students behave very well but feel the behaviour of pupils in Years 7–11 is getting worse. A number of students do not like to leave the sixth-form area because of this."
The E-ACT Academy assured parents they were "confident that Willenhall Academy will continue to make rapid progress" following the critical findings.
Ofsted said E-ACT "has begun to address aspects of greatest concern".
The Academy, which has more than 1,300 pupils, was said to "require improvement" after the previous inspection in March 2015
Ofsted said: "While there is an ambition to address inadequacies and to raise aspirations, there is not yet a sustainable track record in the school to suggest capacity for improvement."Reuse content